Tube cleaner



J. J. HOPPES TUBE CLEANER Feb. 21, 1933.

Filed Feb. 14, 1931 3' Sheets-Sheet 1 INVENTOR ATTO RN EYS 4 Fl I b v.1I MU IW y Feb. .21, 1933. J, HQPPES 1,898,727

TUBE CLEANER Filed Feb. 14, 1931 3 Sheets-Sheet 2 INVENTOR ATTO RN EYSPatented Feb. 21, 1933 sures JOHN a-norrns, or srnme rrntnyonro TUBECLEANER Application-filed February 14, 1931 Serial No.-515,808.

This invention relates'toimprovements in that class'of heat exchangedevices in which a heated "fluid is passedthrough"afluid tight I casing,the heat of this fiuidbe'i'ngtransmittedto a second "fluid passingthrough tubes arranged in the path-of the heated fluid.

The-improved heat exchanger is particu larly adaptedfor use'in suchindustries-as laundries Where large amounts of heated Water unfit forfurther use are available, the heat of which'ma'y be transferred to asupply of clean water of lower temperatures with a consequent increasein 'op'eratingeconomy. Since this hot'waste'water carries a largenmountof foreign matter either in suspension or otherwise, the depositingthereof on the tubes loWe'rsthe' efiiciency of .the heat transmission,the deposit or sludge aeting'as an insulator. Heretofore, heatexchangers have beencleaned by removing portions of the casingandscrubbing'theinterior memberswith'brushes, or by attempting to wash awaythe'ac'cumulations bywater under pressure as froma hose, either methodrequiring that the device be placed out of commission for the timebeing. In the present invention, the cleaning operationmay be.carriedout at anytime desired without in 'terference with the normalfunctioning of the device'as a heat'reclaimer, and, being preferably.power-driven and automatically stopped,-the' labor cost is -greatlyreduced.

The object of: the invention is. to provide means whereby theconvenientand economical removal of sludge from the surfaces of cleanfluid conduits or: tubes is carried out. In the accompanyingdrawings:

Fig. '1 is afront'elevation'of a heat exaway to shovv portions of theinterior de-. tails.

1 Fig. '5 is an enlarged fragmentary elevation in perspective-showing aportion of the cleaning apparatus.

Fig. 6 is an enlarged fragmentaryvertical section on'the line 6-6of-Fig. 1, showing a portion of the'cleaning device together withpartial details of the tube and header construction.

Fig. 7 is an enlarged fragmentary longitudinal section on the line 77 ofFig. 4.

Fig. 8 is a fragmentary vertical section on the line 8-8 of Fig. 2.

Fig. 9 is an enlarged'partial elevation of the left hand end of thedevice, aportion of theview being a vertical section on the line 9--9of- Fig. 1.

Fig. 10 is an enlarged fragmentary horizontal section on the line 10-10. of Fig. 9. Fig. 11 is a vertical section through an assembly of someof the details.

Referring to the drawings,the casing. of the improved heat-exchangerisessentially a fluid-tight sheet-metal box, admission and dischargeopenings for the fluid giving up its heat, hich willherezifter be termedthe hot or Waste Water, being in the nature of long, rectangularopenings in the lowermost 7 portions of the end Walls. 1represe-nts'the' upper sheet, 2 the bottom or floor member, 3 the rear,and at the front Wall. The waste water enters at6 and flows into'apreliminary, hopper-shaped settling chamber 7 wherev aportion ofthesludge is deposited. This "cham'berfis formed-by an outer wall 8extending upwardly from the extension 2' of the'floor sheet-2 to apointabove the level of the'upp'er casing sheet 1. I

The s ettlingchamber'7 is closed at its upper end'bya horizontal sheet9-secured to the upperedges of the Wall 8 and to. a Wall memberlO vvhichin turn is secured to the righthand edge of the upper-sheet 1. Thechamber has a sloping bottom 11 for the greater portion ofits'extent'for thepurpose offacilitat ing the deposit of vany sludge, theslope causing the sludge to gravitate to" the bottom 7 of'the'chamberfrom where it may be drained oif'at intervals throughthe drain-pipe 12.

..will appear at a later point.

The flow of hot water is turned downwardly on entering the settlingchamber as shown by the arrows in Fig. 2, then upwardly. there being avertical bafile member 13 longitudinally disposed in the chamber 7 therebeing a horizontal wall 13 which closes the space in the settlingchamber above the inlet on the outer side of the baflie so that allwater must pass beneath the battle in proximity to the inclined bottom11. The end wall 5 of the casing forms one side of the chamber andextends upwardly to a point not less in height than the level of theupper casing member 1 and provides an opening 1a between the upper edge5 of the wall member 5 and the chamber top member 9. This opening l icommunicates with a vertical channel 15 formed between the end wall 5and a partition member 16 placed in parallel relation there with andpreferably extending the full width of the casing from front to rear,the front and rear walls of the channel 15 being extensions of the wallmembers 4 and 3, respectively. The hot water then flows downwardlythrough this narrow vertical channel 15 and into the casing through anopening 17 below the bafiie member 16, the battle 16 extending to withina short distance of the floor 2 of the casing.

The accompanying drawings show a casing whose interior is divided intotwo compartments by a single vertical, transversely disposed partitionmember 18 in parallel relation with the end walls and joined at itsupper front and rear edges preferably by fluid-tight joints to the uppermember and front and rear walls 4 and 3. This partition also extends towithin a short distance of the floor 2, providing a horizontal opening19 similar to the opening 17. The two compartmentsmentioned aredesignated C and C,

and are termed heat-exchangingchambers,

since in each chamber are inserted interconnected, unitary structurescomprising tubes. headers and other associated details in which thefluid to be heated is passed." In the present specification the fluid.being heated is termed simply the clean water, while the de;

scription of the conduits carrying the same the chamber C is undulatory,the Water arming immediately on entering the chamber through the opening17 by virtue of its heat. As it ascends, heat is lost and the velocityof this upward current is reduced, and on impinging on the'under surfaceof the upper sheet 1 is diverted to the left, flowing downwardly throughthe left side of the chamber 0 along the partition 18 towards theopening 19. The opening 19 is, of course, the inlet opening tov thechamber C, wherein a repetition of the flow just'described occurs.

The outlet for the chamber C is also adjacent the floor member 2 in thesame manner as the openings 17 and 19 are arranged and is designated asat 20, Fig. 1. The flow after passing through this opening 20 isupwardly through a narrow vertical passage 21 formed by the parallelposition of a bafiie sheet 22 and the end wall 23 at the left extensionof the casing. The passage 21 discharges into an enclosure comprisingthe walls 24, 25 and 26, F ig 7 in connection with suitable front andrear wall extensions forming a fluid-tight passage-way leading to thedischarge connection 27, it being noted that the flow through theenclosure reaches an altitude greater than the level of the upperportions of the casing, as the edge 23 of the end wall 23 extends abovethe upper sheet 1, in the same manner as described in connection withthe upper edge 5. The advantage gained-in causing the incoming andoutgoing flows of hot water to be at greater elevations thanthe upperportions of the casing is that the casing at all times remainscompletely'filled with water whether in operation or not, therefore anysludge that may be deposited within the casing or pas sages leading toand from the same, or upon the clean Water conduit arrangements, remainsin a more plastic condition, being prevented from drying and consequenthardening which would result in an expensive clean ing operation. Thisconstruction also permits the drainage of the settling chamber 7 withoutlowering the level of the water in the interior of the casing.

By causing the waste water to enter and leave at the lowermost portionsof the casing the previously mentioned advantage is gained of allowinga. short-circuiting of any occasional quantities of colder waste water,the path of such being comparatively direct from the casinginlet 17 tothe outlet 20, the water, by its greater density remaining near thefloor. A further minor advantage is that, by the provision of'hand-holeopenings normally covered by cover-plates such'as are indicated at 28,Fig. 2, and at 29, Fig. 4., access may be hadto the floor area of thecasing forinspection or such cleaning. thereof as may be desired." Thecasing maybe drained by opening a valve (not shown) connected with adrain-pipe 30 preferably located near the Casing outlet 20. I

The improved heat-exchanger is designed I to provide that a modificationof the effective counter-flow scheme is employed, the path of the flowof clean water receiving heat starting at the lower left extremity ofthe device and terminating at the lower right portion in proximity tothe waste water inlet. It is clear from the description so far that thepath followed by the waste water is a series of undulations moving fromright to left, andthat a chamber suchas C encloses a single undulationconsisting ofja descending and ascending column of water ofsubstantially rectangular cross-sectional area.

The simplest counter-flow arrangement would be to cause the path oftheclean water to closely conform to the undulatory path of the waste waterin all respects, but I preferan ascending column, of waste water. The

exact relation of the paths one to another may be stated in other-wordsby explaining that a cross-section taken on a horizontal plane througheither an ascending or descending column ofv waste water issubstantially rectangular in form, the long dimension extendingfromfront to rear, and that the path of the clean water within thecasing is always parallel to the long dimension.

Such an arrangement has'an advantage in that an extended clean waterpath is provided in-a relatively small space. There is also an advantagethat it is possible that a desired number of tubes and associated partsmay be combined into a unitarystructure of which a plurality areemployed, each of which may be inserted or withdrawn'into or from the Ycasing independently of the others, all connecting mediums conveyingfluids from one to another of the structures being made on the outsideof the casing.

The clean water is conveyed throughout the casing interior in tubes 31ofwhich a preferably equal number is associated in each unitarystructure or bank, in the present case there being two banks for eachsingle heat exchanging compartment such as C or C. The tubes arearranged in vertical and horizontal rows, asseen bestin Figs.:1 and 5,although it is clear that a staggered arrangement could be employed.Referring to the initial bank, employed in the left portion of thechamber C, the tubes are secured at their forward ends in a. flatplate-32 and at their farther ends in the raised-portion'33 of a hollowheader 33 preferably by a rolling and calking process,:this operation attheirconnection with the header 33- being performed through openings inalignment with each tube,

The front wall 4 of the casing is provided with rectangular openings 4through which the openings being closed by the plugs the unit isinserted into the casing. Rollers 33 are fitted to the bottom portionsofthe headers 33 whereby greater ease of assembly maybe secured. -Theplate '32 is sufficiently large to act as a cover foran opening 4' andthrough the overlying portions of the plate 32 screws are insertedwhichthread into openings'in the front'wall 4, and also passing throughtheoverlying-flange 34' of a dishshaped cover casting 34. The dishedinterior of the cover casting isdivided into compartments byhorizontalbafiies 35 and 36 into the compartments 34 34 and 34, thesebaffles being of such height as to bear against the plate 32 andeffectually prevent the passage of fluid from any compartment toanother. In the rear header 33 an integral baffie 37 is'emp'loyed,-which divides the interior of this header into twocompartments 33 and 33. The alignment of the baffles 35 and 36 in thecover 34 in relation to the bafiie 37 in the header 33 is such that thecompartment communicates with a plurality of tubes which dischargeinto'the lowermost portion of the compartment 33, while tubes leadingfrom the uppermost portion of the compartment discharge into thelowermost partof the-compartment 34 The tubes in communication with theupper portion of the compartment 34 lead to the lower portion of thecompartment 33 in the rear header,

and fromthe upper part of this latter compartment the tubes dischargeinto the compartment34 at the upper end portion of the cover 34.

Openings '38 and 39'are provided in the raised portion of the covercasting 34, the opening 38 being an inlet opening where the clean watermakes its initial entrance into the conduit arrangen'ient, communicatingdirectly with the compartment 34, while the opening 39 communicates withthe compartment 34. It will then be seen that the clean water flowinginto the compartment 34 travels rearwardly throughthe lower tubes intothe compartment 33 and is then returned forwardly to the compartment 34then again in a rearwardly direction into the lower part of thecompartment 33, then forwardly into the compartment34 and outwardlythrough the opening 39. Alternate movements are thus made in adirectiongenerallyiupward, and since the bank as just described occupiesthe left hand portion of the chamber C in which portion a descendingcolumn of'waste water is flowing, a heat transfer in accordance with thepreferred modified form of counterfiow takes place.

The water issuing from the upper compartment 34 passesthrough theopening 39 and through a hollow duct 40' into theupper compartment 34 ofthe cover 34 of the succeeding-bank of tubes, which bank is placed inthe rightside of the chamber C. By admitting the fluid to thiscompartment, which is in fact the compartment 34 of the second bank, thewater flows towards the rearward header and thereafter in a generallydownward direction to the opening 38 in this bank, and is-then conveyedby the duct 41 to the succeeding banks. The generally downward movementof the clean water in this bank is also in, a direction counterwise tothat of the waste water, which in this half of the chamberis upwardly.The fiow of clean water continues as described through all of theplurality of banks of tubes, finally issuing at the outlet opening 38 inthe bank nearest the waste water inlet 17.

A plurality of banks such as have just been described are employed inthe heat exchanger. The present drawings show four only, these beingplaced two each in a single compartment such as C or C, therefore thereare two forward and two rearward movements of the clean water for eachascending or descending columns of waste wa ter, or sixteen to and fromovements for two undulations in the heat exchanger illustrated in thedrawings. This provides perhaps the shortest path practical for eitherof the fluids for an exchange of heat of any appreciable economy;certain circumstances may indicate that a more complete abstraction ofthe available heat units in the waste water may be made by providing alonger path for the fluids. The design of the present exchanger lendsitself to such extensions as it isonly necessary to employ additionalchambers and banks of clean water conduits, using the casing andconstructions as described, it being understood that a partition 18 isemployed. between adjacent chambers.

As has been previously mentioned, the deposit of sludge on the outersurfaces of the tubes 31 interferes with the effective transfer of heatto the cooler fluid, therefore to maintain the efficiency of the deviceat an economical rate, frequent removal of the greater portion of thesludge is necessary. To this end a mechanism, preferably operated by anelectric motor, is employed for each bank of tubes, and all suchmechanisms being preferably operated simultaneously.

T -e essential detail of the cleaning mechanism is a fiat, perforatedmetallic plate 42 in which are openings 42 slightly larger in diameterthan the tubes 31. These openings are regularly spaced to the samedimensions as the spacing of the tubes, so that the plate may be placedon the tubes in an interposed relation between the forward tube plate 32and rear header 33, this being done at the time of the assembly of abank. It will then be clear that a movement of the plate 42 from oneextremity to another of the exposed tube surface will remove by anagitating action the greater portion of any matter adhering thereto. Themovement of the plate in operation is an alternate to and fro movement,produced by rotating a pair of screw-threaded rods simultaneously ineither direction. The screw-threaded rods are indicated at 43 and 44,and are alike, and as seen best in Fig. 5, are arranged in parallelrelation to the tubes, one above and below the bank thereof. The rodsare rotatably mounted at the rear ends in the lugs 45 and 46, projectingupwardly and downwardly, respectively from the central portions of theupper and lower extremities of the header 33, Fig. 4, and at theirforward ends in a bearing comprising a partial bearing in the innersurface of the cover 34 and a more extensive bearing in a gland 48concentrically positioned in the outor extremity of a boss 49 projectingfrom the cover 34 at the upper and lower portions thereof. Thoseportions of the screw rods 43 and 44 that are rotatably mounted in thebearings just described are in the nature of reducer'l-diameter extendedportions indicated at 43 and 44, 43" and 44", respectively referring tothe forward and rearward portions of the rods, one only of the forwardbearing arrangements being shown in the drawings, i. e., a forward upperbearing as seen in detail in Fig. 6. The gland also acts to compress thepacking material 50 placed around the portions 43 and 44 of the screwrods, being forced in place by a plate 48' in order to prevent anyleakage of fluid through the forward bearings described. The plates 42are provided at their upper and lower extremities with re-enforcingcasting members 51 and 52 having in their central portions bosses 53which are interiorly threaded to receive the screws 43 and 44. Thescrews are rotated in the present instance by a reversible electricmotor 55 mounted in any convenient location on the forward side of thecasing. The motor is connected by a speed reducing mechanism shownconventionally at 56 to each of the plurality of screws 43 and 44 bysprockets and a chain. The sprockets are shown at 57 and are fixed inalignment on the extended reduced diameter portions 43 and 44 previouslymentioned and over all sprockets the chain 58 is passed. At suitablepoints idler sprockets such as are indicated at 59 are employed,

whose function is merely to cause the chain 58 to more closely hug thesprockets and thereby prevent climbing of the chain upon the sprocketteeth. The speed reducing mechanism is preferably connected to a furtherextended portion of one of the screws 43, the extended portion 43passing through and keyed to the master gear (not shown) of the speedreducing device 56. Y

The motor is started and stopped by closing and opening the'double polereversing switch indicated conventionally at 61. In the presentinstance, the motor is started manually by throwing the switch to aclosed circuit position, and since the normal position of the scraperplate 42 when not in operation is at one end of the exposed tube surfacea simple switch operating device permits the starting of the motor onlyin the direction it may run to cause movement of the plate towards theopposite end, thereby preventing damage to the parts. This mech anism isalso employed to stop the motor automatically and therewith the movementof the plate at the completion of a traverse of the plate along thetubes.

uses-#27 At convenient location in proximity to an agitator plate 42,preferably at the upper end of the plate nearest the switch location, isarranged a rod 62 in parallel relation to the travel of the plate 42.This rod extends rearwa-rdly through the rear wall of the casing to theoutside, and has a slidable bearing in a stufling box arrangementcomprising a bored body portion 63 and the gland 64, while the forwardend rests in and has a slidable bearing in a thimble 65 inset in anopening in the cover casting 34 leakage being thus prevented at eitherpolnt mentioned. On the rod 62 at suitable positions within the casingare check nuts 66 which make contact with a lug 67 projecting from theupper surface of the plate casting 51 through which lug the rod 62 ispassed.

On the outer rearward extension 62 of the rod 62, Fig. 9, isa pair ofcheck nuts 68 and 69 spaced apart as shown, between which is interposedthe upwardly disposed forked end of a lever 7 0 secured to a horizontalrock shaft 71 held in suitable bearings 71'. The shaft 71 terminates ata suitable point above the switch 61 and on the end thereof is a lever72 which is substantially horizontally disposed. To the free end of thelever 72 a downwardly hanging rod 73 is pivotally connected, while thelower end of this rod is pivotally connected with a crank-pin 74projecting eccentrically from a disk 75 loosely rotatably mounted on astud 76. The stud 76 is secured in a bracket 78, in concentric alignmentwith the center of rotation of the switch arm 77, the bracket 78 beingthe means of support for the switch box and being suitably attached to aconvenient portion of the heat exchanger casing. V

Projecting from the disk 75 in proper angular displacement as regardsthe crank-pin 74 (in the present case, on the side opposite the pin 74)are pins 79 which, on partial rotation of the disk in either directionalternately make contact with the switch-arm 77 to cause the switch tobe thrown to the open or neutral position as shown in full lines inFigs. 4 and 9.

This movement is the only function of the pins 79 in the present case,although it will be clear that with a suitable switch and link age theplates 42 may be given a continuously reciprocating movement as long aselectric current is supplied to the motor. With the device as shown, oneof the pins 7 9 (see Figs. 4 and 9) is always in the position it hasassumed on stoppage of the motor, and therefore it is not possible tothrow the switch manually or otherwise to an on-position where damage tothe mechanism may be caused. The position of the switch arm 77 as seenin dotted lines in these figures is seen to be the only permissibleposition in which it may be placed.

The operation of the heat exchanger as a unit issimply to allow the warmwaste'water to-pass through the casing-in the manner described, theclean water absorbing the greater percentage of the heat thereof throughthe walls ofthe tubes 31; As the sludge deposit: develops on the tubes,the operator places-the switch arm in the closed circuit positionallowable by the linkage connection, whereupon all the plates 42' aremoved simultaneously in the proper direc tion, and on approaching theendof the stroke the movementof the rod 62' by the plate with which itis. connected throws the switch to the neutral position through thelinkage: de scribed.

The 'weigh-t'of each plate 42 is imposed on itsscrews 43 and 44inorderto prevent wear of the tube surfaces. Due to the fact that the openingsin each plate 42 are larger than the tubes and the plates are supportedby the screws, the. sludge will be removed from the tubes by agitationofthe liquid set up by the plates moving therethrough as distin; guishedfrom a scraping action, this arrange ment obviating any wear upontheouter surfaces of'thetubes such as would be occasioned by a. scrapingaction with the scrapers in direct contact with the tubes' The. sludgethus removed 'issetfree and is carried in the currentof the, flowingwaste water and since a large percentage of the sludge is of the sameapproximate specific gravity it: is readily carried out through-thevertical'casing discharge passage21, which is somewhat. restricted toincrease momen tarily the velocity of the flow at thispoinh In the useof the apparatusto heatorcool oil or any liquid with high viscosity orwherever desired the agitators can'be operated continuously to keep thetubes free of viscous substances or sludge and thusincrease theheattransfer through the tubes by keeping them free from suchsubstances; i

I have filed a; divisional application on January 25, 1933, and bearingSerial Nume ber.653,461 for thesubject matter of the heat exchangedevice described in this application.

Having thus described my invention, I claim:

1. In a cleaning mechanism for the exterior of tubes arranged in a bank,a member arranged transversely of the series of tubes and havingsurfaces surrounding the exterior of the tubes, means for moving saidmember longitudinally of the tubes, said means including an electricmotor, and means for automatically stopping the motor at a predeterminedpoint in the movement of said member. I

2. In a cleaning mechanism for the exte rior. of tubes arranged in abank, a member 6 arranged transversely of the series of tubes ofthelength of said tubes upon which said member is threaded, means forholding said member from turning, means for revolving said screw, saidlatter means including an electric motor, and means for automaticallystoppingthe motor atva predetermined point in the movement of saidmember.

3. In a cleaning mechanism for the exterior of tubes arranged in a bank,a plate-like member having a plurality of perforations, one for eachtube, the walls of said perforations having a loose fit with therespective tubes to permit the member to move longitudinally thereof, apair of screws extending parallel with the tubes upon which said memberis threaded, and means for rotating said screws simultaneously at thesame speed to cause said member to travel in an endwise direction withrelation to said tubes.

4. In a cleaning mechanism for the exterior of tubes arranged in a bank,a member having surfaces surrounding each tube and movablelongitudinally of the tubes, means for moving said member including areversible electric motor, a switch for controlling the circuit of saidmotor having a movable member with an off-position and an onposition oneach side of the off-position, means operated by said cleaning mechanismfor moving the movable member of said switch to the off-position at apredetermined point in the movement thereof, and means for automaticallylocking said movable member against movement to one of saidoil-positions when thrown to neutral position.

5. Ina cleaning mechanism for the exterior of tubes arranged in a bank,a member arranged transversely of the series of tubes and havingsurfaces surrounding the exte- .r1or of the tubes, power-operated meansfor moving said member longitudinally of the tubes and means forautomatically stopping the power-operated means at a predetermined pointin the movement of said member.

In testimony whereof, I have hereunto set my hand this 7th dayofFebruary, 1931.

JOHN J. HOPPES.

